This is generally an easy mission as long as you properly handle the Nebelwerfers at the start. If you charge them right away, you will have a very hard time later. If you don't have enough Shermans, you may also have an annoying time.

Enemy infantry can pick up weapon drops like Panzerschreks. They can also throw grenades, but apparently only at Observation Posts (see picture below).

Part 1 - Barracks and Initial Troops

Two buildings are indicated as potential field barracks. Choose the one furthest from the Nebelwerfers (i.e. to the southeast -- see picture below).

Although the Nebelwerfers can bombard near you, they can't really reach the building, though you need to be careful and pull your troops back.

The surrounding area is generally too hostile for infantry unless you are prepared to accept squad member losses, but your jeep can take out some enemy infantry if you are careful to keep it repaired.

Quickly get two Snipers and start clearing the immediate area.

In the video below, you can see the mess that results if you pick the first building you see, and if you charge the Nebelwerfers right away (start at video time ~2:10).

Shortly after establishing the Barracks, a Panzer will patrol the area.

Retreat and hide. If it doesn't detect enemies or if enemies quickly pull back out of its visual range, it will continue on and park further away and be temporarily no threat.

Based on its position, secure what Stategic Points you can without drawing its attention.

Part 2 - Nebelwerfers

Do NOT destroy all the Nebelwerfers yet.

Snipe the crew of two and keep reconnoitering and sniping while you finish building base structures, getting upgrades, and finalizing your forces.

Instead of destroying the Nebelwerfers, snipe them so you can use them yourself later in lieu of mortars.

If you penetrate too deeply into enemy territory, tanks become more active and you may not be ready, so either don't explore too deeply or build a couple of Shermans.

Because these reinforcements may put you over the Population Cap, prior to taking out the Nebelwerfers, think carefully:

The Medal requires that at least one Ranger squad reaches Veterancy Rank 3.

If these reinforcements put you over the Population Cap, you will not be able to restore Ranger losses by Reinforcement, possibly making the Medal impossible unless you deliberately lose units to bring your forces under the Population Cap. Each Ranger model costs 2 Population Cap.

There are endless Panzer reinforcements from off-map to the north, and from the central compound / Town Hall area that the Germans have secured -- yes, tanks magically appear from nowhere, even if you have destroyed their production buildings (Krieg Barracks and Sturm Armory). for this reason, it is nice to have at least four Shermans (not Crocodiles) to double-team Panzers.

At Expert Difficulty, even a level 3 Veterancy Sherman can have trouble with the Panzers here, and because they sometimes appear with their machineguns manned (indicating they are Veterancy level 2 or 3), you can't always reliably have Engineers repairing your tanks in the middle of the fire exchange.

In order to ensure you have enough Shermans, you need to build them first before the reinforcements, or be willing to let infantry die to make room in your Population cap.

If you want to maximize your Population Cap of 75 (prior to reinforcements arriving), I recommend 3x Shermans, 3x Engineer squads, and reinforcing one of the 4-man squads of Riflemen to 6, for a total of 75/75 if you haven't lost any Rifleman models so far. Then kill the crew of the last Nebelwerfer and use Riflemen to crew the Nebelwerfers.

Once you have the Nebelwerfers, you should not need mortar teams, and you will generally not need mortar teams in the early game as you should be able to get by with a pair of snipers.

Get the M1918 Browning Automatic Rifle (BAR) prior to picking up Nebelwerfers as this may cause a Rifle to be dropped by the Riflemen squad, and thus picked up by another unit.

The Rangers cannot pick it up if they already have the short-range .45 ACP M1 Thompson Sub-Machine Gun upgrade, which replaces all four squad guns (but not the M9 Bazookas).

Part 3a - Ranger Veterancy

For the medal (Army Ranger Badge), at least one Ranger squad must be promoted to level 3 Veterancy.

A fairly good way to do this is to have a tank distract the enemy and follow up with Rangers. This, however, will not guarantee all squad members survive or that the enemy won't change targets. On Expert Difficulty, even regular infantry can kill off at least 1 ranger, depending on how long a skirmish lasts. If you are unable to Reinforce the Rangers due to being over the Population Cap, try to instead:

Target smaller squads and overwhelm them with both the Ranger squads.

Attack weapon crews which are typically weaker when engaged up close (e.g., AT guns).

Throw grenades from behind obstructions such as hedges or buildings.

(picture below) Trying to distract the Ostwind for Rangers to kill it for Veterancy, but with the SMG upgrade, Rangers tend to rush in close to allow their SMGs to hit the target, regardless of whether they can actually damage the target or not. The Ostwind could at any time switch targets to mow down the Rangers.

(picture below) A much safer way to gain Veterancy: Throwing grenades over obstructions, such as this ruined building.

Part 3b - Clear Map, Capture Strategic Points

The rest of this map is easy, but slow if you want to avoid losses. Keep your tanks in front and reserve your infantry for capturing Strategic Points. Jeeps can sometimes spot for you but Snipers are better, especially if you have gotten them to Veterancy level 3 (when they can move at full speed while camouflaged).
When you are very close to the central area (which is bounded by obstacles and impassable rubble), watch for mines. There are some on the east side where the lanes are tight and there are several AT guns. Any annoying areas such as these can be cleared with sustained Nebelwerfer barrages to protect your tanks.

Do not bother trying to capture the Town Hall / centre of the map. You can bombard inside and take out the Kreig Barracks and Sturm Armory, but the enemy will continue to receive Panzer reinforcements, even from within the compound.
Also, if you hit the Town Hall with anything, Panzerschrek-equipped Stormtroopers will appear from off-map and beeline to the Town Hall as reinforcements (see below).

The Stormtroopers are not as dangerous as they seem because they stop for nothing. They will shoot along the way, but because they don't stop to engage you can chase them with tanks, or alternatively let them go to the Town Hall then bombard the lot of them from a distance.

Once you capture all the necessary Strategic Points, the mission ends in success.